Description of this collection of datasets: Moulins are important conduits for surface meltwater to reach the bed of the Greenland Ice Sheet. It has been proposed that in a warming climate, newly formed moulins associated with the inland migration of supraglacial lakes could introduce surface melt to new regions of the bed, introducing or enhancing sliding there. By examining surface strain rates, we found that the upper limit to where crevasses, and therefore moulins, are likely to form is ~1600 m. This is also roughly the elevation above which lakes do not drain completely. Thus, meltwater above this elevation will largely flow tens of kilometers through surface streams into existing moulins downstream. Furthermore, results from a thermal ice-sheet model indicate that the ~1600-m crevassing limit is below the wet–frozen basal transition (~2000 m). Together, these datasets suggest that new supraglacial lakes will have a limited effect on the inland expansion of melt-induced seasonal acceleration.Description of the files: FrozenOver2000.dbf, FrozenOver2000.shp, FrozenOver2000.shx: Creator(s) of the data: Kristin Poinar --- Title of data: Lakes with floating ice cover in the summer of 2000. --- Date created: May 2014 --- Abstract: Supraglacial lakes with floating ice covers on the western Greenland Ice Sheet were identified using Landsat and Radarsat imagery. These shape files give the locations and approximate boundaries of all such lakes (570) in the year 2000.
Description of the files: FrozenOver2010.dbf, FrozenOver2010.shp, FrozenOver2010.shx: Creator(s) of the data: Kristin Poinar --- Title of data: Lakes with floating ice cover in the summer of 2010. --- Date created: May 2014 --- Abstract: Supraglacial lakes with floating ice covers on the western Greenland Ice Sheet were identified using Landsat and Radarsat imagery. These shape files give the locations and approximate boundaries of all such lakes (387) in the year 2010.
Description of the files: FrozenOver2013.dbf, FrozenOver2013.shp, FrozenOver2013.shx: Creator(s) of the data: Kristin Poinar --- Title of data: Lakes with floating ice cover in the summer of 2013. --- Date created: May 2014 --- Abstract: Supraglacial lakes with floating ice covers on the western Greenland Ice Sheet were identified using Landsat and Radarsat imagery. These shape files give the locations and approximate boundaries of all such lakes (183) in the year 2013.
Description of the file: Streams2004_2014.dbf, Streams2004_2014.qix, Streams2004_2014.shp, Streams2004_2014.shx: Creator(s) of the data: Kristin Poinar --- Title of data: Surface streams in western Greenland in the summer of 2004. --- Date created: May 2014 --- Abstract: Surface streams occurring on the western Greenland Ice Sheet in the summer of 2004 were identified using Landsat and Radarsat imagery. These shape files give the locations and paths of the 247 approximately largest surface streams in the area in 2004.
Description of the file RacmoSurfaceMelt_mmyr.csv: Creator(s) of the data: Kristin Poinar, Jan T. M. Lenaerts, Michiel R. van den Broeke --- Title of data: Surface melt from RACMOv2.3. --- Date created: December 2014 --- Abstract: Output from RACMO regional climate model, version 2.3, for the total melt (ice melt plus snow melt) on the ice-sheet surface within the study area in western Greenland. Data are averaged into elevation bands, e.g., 0-200 meters elevation, which are given in the first two columns for each row. The data are also averaged in time to one year resolution (1958-2013); these data appear in the following columns. Surface melt is given in mm/yr, water equivalent.
Description of the file StudyArea.csv: Creator(s) of the data: Kristin Poinar --- Title of data: Outline of the study area in western Greenland --- Date created: July 2014 --- Abstract: The analyses presented in this paper were performed on the areas of the ice sheet inside this polygon.
Description of the file WetBed_FoxMaule.csv: Creator(s) of the data: Kristin Poinar --- Title of data: Modeled basal temperate area in western Greenland using Fox Maule et al. (2005) geothermal flux. --- Date created: July 2014 --- Abstract: Results of the thermal model runs in western Greenland using geothermal flux from Fox Maule et al. (2005) as a boundary condition. The (x,y) points in this file outline the wet-bedded region: the model predicts that points inside the polygon have a wet (temperate) bed.
Description of the file WetBed_ShapiroRitzwoller.csv: Creator(s) of the data: Kristin Poinar --- Title of data: Modeled basal temperate area in western Greenland using Shapiro and Ritzwoller (2004) geothermal flux. --- Date created: July 2014 --- Abstract: Results of the thermal model runs in western Greenland using geothermal flux from Shapiro and Ritzwoller (2004) as a boundary condition. The (x,y) points in this file outline the wet-bedded region: the model predicts that points inside the polygon have a wet (temperate) bed
